Power hand held routers have become a common and useful woodworking tool for working edges, making grooves of different shapes and sizes, cutting dadoes, and making rabbit cuts. However, the router can be a difficult tool to use skillfully without a guiding device. Although prior art router jigs have attempted to provide such guiding devices, these prior art router jigs have proved to be cumbersome to use, difficult to set up, and limited in application to specific routers and specifically shaped workpieces.
Two examples of prior art router jigs are illustrated in U.S. Pat. No. 2,957,507 to John Vargo and U.S. Pat. No. 3,967,665 to Allan M. Lund. Both of these patents describe router jigs which provide a means for guiding a router. However, both these structures require awkward and time consuming alignment and set up procedures.
U.S. Pat. No. 3,967,665 to Lund describes a routing template assembly having an adjustable elongated slot which defines the area to be cut on a workpiece by a router bit having a guide bushing. As described in the patent, the procedure for adjusting the elongated slot to the desired width requires several time consuming steps which includes the measurement of the radius of a guide bushing used to guide the router and the measurement of a piece of material which defines the width of the slot to be cut on the workpiece. Each of these measurements requires the relevant adjustment of several parts of the jig and the tightening of several screws.
The structure described in U.S. Pat. No. 2,957,507 to Vargo is a routing jig which provides a fixed rectangular frame which contains the body of the router within a specified area. By containing the body of the router, the frame defines the boundaries of movement for the router and thus defines the area cut on the workpiece. However, the width of the Vargo horizontal guide structures is not adjustable and the initial alignment of this structure is awkward and time consuming. The Vargo device also fails to provide an easy and simple method for aligning the device with respect to the area that is to be cut and also fails to provide the versatility of application with respect to different brands of routers which may have different size bases.